Forces

Which of the forces below is a contact force?

• magnetic force

• friction

• gravity

• weight

When a box is resting on a surface (no motion), what force balances out the downward force of gravity?

• acceleration force

• normal force

• friction force

• there are unbalanced forces

Amy is holding her notebook by her side as she runs to class. Which of these forces are acting on her notebook?

• gravity

• friction/air resistance

• applied force

• all of these

Macy is sitting at her school desk surrounded by her classmates and school supplies. Which of the following objects exert a gravitational force on her?

• the desk

• her textbook

• the boy next to her

• all of these

The gravitational force depends on…

• the masses of the objects and the volume of the objects.

• the volume of the objects and the distance between them.

• the size of the objects and the amount of matter in them.

• the masses of the objects and the distance between them.

A force which opposes motion when two substances rub against one another is called…

• friction

• normal force

• applied force

• magnetism

Which of these statements best describes “weight”?

• Weight is the amount of matter in an object.

• Weight is how much mass something has.

• Weight is the effect of a gravitational force on a mass.

• Weight is how hard it is to move an object.

If you weigh 100 pounds on Earth, you would only weigh about 17 pounds on the Moon. Which statement below BEST explains why?

• Your mass would be less on the Moon, so the Moon will exert less gravitational force.

• The Moon has less mass than Earth, so it will exert less gravitational force on you.

• The Moon is farther from the Sun, so it will exert less gravitational force on you.

• A pound is worth more on the Moon.

Which pair of objects has the least gravitational force between them?

• Two 1 kilogram objects 2 meters apart

• Two 1 kilogram objects 4 meters apart

• Two 2 kilogram objects 2 meters apart

• Two 2 kilogram objects 4 meters apart

Unbalanced forces acting on an object may result in which of the following?

• the object’s speed may increase

• the object may change direction

• the object’s speed may decrease

• any of these